Gun Barrel or Sleeve Therefor

ABSTRACT

A gun barrel or sleeve for a gun barrel is provided. The invention includes staggered helical arrays of elliptical or oval blind cavities along the length of the gun barrel or sleeve. As a sleeve, the invention may be press-fit or force-fitted over a regular barrel or a barrel of reduced wall thickness. The cavities have radially extending orifices by which an angular width of an interior portion of a cavity is greater than an angular width of the orifice of that cavity, and a longitudinal dimension of the interior portion of that cavity is greater than a longitudinal dimension of the orifice of that cavity. The product may be produced by additive manufacturing, autofrettage, casting, forging or traditional CNC machining.

CROSS REFERENCE TO RELATED APPLICATION

This non-provisional utility application claims the benefit of and priority to U.S. provisional application Ser. No. 63/157,862 “Gun Barrel or Sleeve Therefor,” filed 8 Mar. 2021. The entire contents of U.S. provisional application Ser. No. 63/157,862 “Gun Barrel or Sleeve Therefor,” filed 8 Mar. 2021 is hereby incorporated into this document by reference.

COPYRIGHT STATEMENT

A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.

FIELD

The invention relates to gun barrel manufacturing and resultant structures.

BACKGROUND

In the manufacture of gun barrels, two conflicting constraints are providing sufficient wall thickness to withstand the internal pressures of the projectile propellant during combustion or deflagration, and providing a structure without excess mass. Two other conflicting constraints are providing a material which is ductile enough to resist crack development or rupture over a service life of many transient internal pressure events, while also providing material rigidity or sectional strength to assure accuracy.

Additionally, rapid thermal dissipation of propellant heat requires that a gun barrel must also act as an effective radiator of heat because barrels which fail to cool quickly enough tend to wear out and incur the material and logistical expenses of frequent replacement, are less accurate in use while hot, and slow cool-off time may reduce the maximum fire rate of a repeating weapon.

Recent experiments in reducing steel barrel wall thicknesses while attempting to reinforce the barrel with carbon fiber or similar composites have not yet resulted in satisfactory products or performance, so opportunities for improvements in strength to mass ratio and in thermal rejection remain desirable in industry.

BRIEF DESCRIPTION

Gun barrels must provide several material and sectional properties in order to be most effective and serviceable.

A primary objective of the invention is to provide a gun barrel or a sleeve for a gun barrel which the internal pressures of the projectile propellant during combustion or deflagration.

Another objective of the invention is to provide a serviceable structure for gun barrel or a sleeve for a gun barrel which provides sufficient rigidity for accurate fire and durability in service without including excess mass.

Yet another objective of the invention is to provide a material for a gun barrel or a sleeve for a gun barrel which is ductile enough to resist crack development or rupture over a service life of many transient internal pressure events.

Another objective of the invention is to provide a gun barrel or a sleeve for a gun barrel which allows for rapid thermal dissipation of propellant heat between successive firing of the weapon.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of particular embodiments may be realized by reference to the remaining portions of the specification and the drawings, in which like reference numerals are used to refer to similar components. When reference is made to a reference numeral without specification to an existing sub-label, it is intended to refer to all such multiple similar components.

FIG. 1 shows an oblique, front top right view of a portion of a gun barrel or sleeve for a gun barrel in accordance with the invention, including two partial cuts along cutting planes [A] and [B.]

FIG. 2 shows a right elevation view of a portion of a gun barrel or sleeve for a gun barrel in accordance with the invention, including a partial cross section revealed at cutting plane [A.]

FIG. 3 shows front view of a portion of a gun barrel or sleeve for a gun barrel in accordance with the invention, including a partial cross section revealed at cutting plane [B.]

FIG. 4 shows a partial cutaway of an oblique, front top right view of a portion of an alternative embodiment of a gun barrel or sleeve for a gun barrel in accordance with the invention.

DETAILED DESCRIPTION of CERTAIN EMBODIMENTS

While various aspects and features of certain embodiments have been summarized above, the following detailed description illustrates a few exemplary embodiments in further detail to enable one skilled in the art to practice such embodiments. The described examples are provided for illustrative purposes and are not intended to limit the scope of the invention.

In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the described embodiments. It will be apparent to one skilled in the art, however, that other embodiments of the present invention may be practiced without some of these specific details. Several embodiments are described herein, and while various features are ascribed to different embodiments, it should be appreciated that the features described with respect to one embodiment may be incorporated with other embodiments as well. By the same token, however, no single feature or features of any described embodiment should be considered essential to every embodiment of the invention, as other embodiments of the invention may omit such features.

In this application the use of the singular includes the plural unless specifically stated otherwise, and use of the terms “and” and “or” is equivalent to “and/or,” also referred to as “non-exclusive or” unless otherwise indicated. Moreover, the use of the term “including,” as well as other forms, such as “includes” and “included,” should be considered non-exclusive. Also, terms such as “element” or “component” encompass both elements and components comprising one unit and elements and components that comprise more than one unit, unless specifically stated otherwise.

The invention relates to a gun barrel or sleeve for a gun barrel, The invention includes staggered helical arrays of elliptical or oval blind cavities along the length of the gun barrel or sleeve. As a sleeve, the invention may be press-fit or force-fitted over a regular barrel or a barrel of reduced wall thickness. The cavities have radially extending orifices by which an angular width of an interior portion of a cavity is greater than an angular width of the orifice of that cavity, and a longitudinal dimension of the interior portion of that cavity is greater than a longitudinal dimension of the orifice of that cavity. The product may be produced by additive manufacturing, autofrettage, casting, forging or traditional CNC machining.

Autofrettage is a metalworking process that typically applies only to components subject to pressures above 15,000 psi, such as liners and jackets for high-pressure pumps, and automotive injection components for high pressure service such as diesel engines. Gun barrels and cannons regularly exceed service pressures where autofrettage becomes an advantageous method of manufacture.

The invention may be fashioned as a gun barrel or as a sleeve compression-fitted over a thin-walled gun barrel. This combination reduces weight while providing exceptional rigidity as a gun barrel is often supported as a cantilever beam, and sectional strength contributes to accuracy. The structure also acts as an improved radiator for dissipating heat from combustion or deflagration when the gun is fired. Rapid cooling extends barrel life and also shortens the time for a heated barrel to cool down to a useable temperature, which increases the allowable rate of fire for repeating arms and fully automatic weapons.

In French, “frettage” refers to the pooping of casks or cylindrical containers to increase strength against internal pressure. Early medieval pieces of ordnance were often manufactured out of closely fitted wood staves caulked or bonded together and lashed with longitudinally spaced apart hoops. These were generally unfit for firing iron or lead projectiles but were capable of lobbing stones worked into spheres. The prefix “auto” means that the material itself withstands the stresses without external devices such as the above-mentioned hoops.

Referring to the figures, FIG. 1 shows an oblique, front top right view of a portion of a gun barrel or sleeve for a gun barrel [1] in accordance with the invention, including two partial cuts along cutting planes [A] and [B.] The barrel defines a longitudinal axis [4,] an interior surface [2,] an exterior surface [3,] and a plurality of angularly spaced apart cavities, with each of the cavities defining a longitudinal length and angular width, and having an orifice piercing the exterior surface but not piercing the interior surface. Typically the interior surface of a gun bore will include rifling such as helically extending lands and grooves or a polygon surfaces rotated as they are translated along the longitudinal axis of the bore. Rifling structures are outside the scope of the invention and are not illustrated.

In the figure, an example of a first plurality of angularly spaced apart cavities is the series including cavities [7 a,] [8 a,] and [9 a.] A second plurality of cavities includes [6 b,] [7 b,] [8 b,] and [9 b] and is longitudinally spaced apart from the first plurality of cavities. A third plurality of cavities includes [6 c,] [7 c,] and [8 c] and is also longitudinally spaced apart from the second plurality of cavities. The second plurality of cavities is radially offset from the first plurality of cavities, and the third plurality is also radially offset from the second plurality, so that a set of similar datum points or features along a first cavity [7 a] from the first plurality of cavities, a first cavity [7 b] from the second plurality of cavities, and a first cavity [7 c] from the third plurality of cavities define a helix [5] along the longitudinal axis of the gun barrel or sleeve.

FIG. 2 shows a right elevation view of a portion of a gun barrel or sleeve for a gun barrel in accordance with the invention, including a partial cross section revealed at cutting plane [A.] Each of the orifices have a longitudinal length [L₁] which is less than the longitudinal length [L₂] of its cavity. Cutting plane [B] is seen edge-on in this view.

FIG. 3 shows front view of a portion of a gun barrel or sleeve for a gun barrel in accordance with the invention, including a partial cross section revealed at cutting plane [B.] In this specification, an angular width dimension may be defined as either an angle subtended between two points with respect to the central axis of the bore, so that the angular width [α₁] of an orifice is seen to be less that an angular width [α₂] of the cavity into which the orifice leads. An alternate way of defining an angular width for a symmetrical feature is to select a centerline passing through the central axis of the bore, and measure widths perpendicular to that centerline. Using this method, it is also seen that the angular width [w₁] of an orifice of a cavity less than the angular width [w₂] of the cavity into which the orifice leads.

Also in this figure, it is seen cavities may comprise a surface which is a convex floor [11,] and may also comprise a concave surface [12] radially spaced apart from the convex floor. Cutting plane [A] is seen edge-on in this view.

FIG. 4 shows a partial cutaway of an oblique, front top right view of a portion of an alternative embodiment of a gun barrel or sleeve for a gun barrel in accordance with the invention. This embodiment may be less preferred than the embodiment shown in FIG. 1, in that although longitudinally spaced apart, the sets of radially spaced apart pluralities of cavities are not radially offset from one set to the next, so that this structure may behave more similarly to a fluted or a splined rifle barrel.

While certain features and aspects have been described with respect to exemplary embodiments, one skilled in the art will recognize that numerous modifications are possible. Also, while certain functionality is ascribed to certain system components, unless the context dictates otherwise, this functionality may be distributed among various other system components in accordance with the several embodiments.

Moreover, while the procedures of the methods and processes described herein are described in a particular order for ease of description, unless the context dictates otherwise, various procedures may be reordered, added, and/or omitted in accordance with various embodiments. Furthermore, the procedures described with respect to one method or process may be incorporated within other described methods or processes; likewise, system components described according to a particular structural configuration and/or with respect to one system may be organized in alternative structural configurations and/or incorporated within other described systems.

The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its spirit and scope. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, are possible from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled.

Hence, while various embodiments are described with or without certain features for ease of description and to illustrate exemplary aspects of those embodiments, the various components and/or features described herein with respect to a particular embodiment may be substituted, added, and/or subtracted from among other described embodiments, unless the context dictates otherwise. Thus, unauthorized instances of apparatuses and methods claimed herein are to be considered infringing, no matter where in the world they are advertised, sold, offered for sale, used, possessed, or performed.

Consequently and in summary, although many exemplary embodiments are described above, it will be appreciated that the invention is intended to cover all modifications and equivalents within the scope of the following claims. 

What is claimed is:
 1. A gun barrel comprising a longitudinal axis, an interior surface, an exterior surface, and a plurality of angularly spaced apart cavities, with each of said cavities defining a longitudinal length and angular width and having an orifice piercing said exterior surface but not piercing said interior surface, with each of said orifices having a longitudinal length less than said longitudinal length of its cavity, and having an angular width less than said angular width of its cavity.
 2. The gun barrel of claim 1, wherein at least one from among said plurality of cavities comprises a surface which is a convex floor.
 3. The gun barrel of claim 2, further comprising a concave surface radially spaced apart from said convex floor.
 4. The gun barrel of claim 1 wherein said plurality of cavities is a first plurality of cavities, and further comprising a second plurality of cavities longitudinally spaced apart from said first plurality of cavities.
 5. The gun barrel of claim 4, wherein said second plurality of cavities is radially offset from said first plurality of cavities.
 6. The gun barrel of claim 4, further comprising a third plurality of cavities longitudinally spaced apart and radially offset from said second plurality of cavities, such that a first cavity from said first plurality of cavities, a first cavity from said second plurality of cavities, and a first cavity from said third plurality of cavities define a helix along said longitudinal axis.
 7. A sleeve for a gun barrel comprising a longitudinal axis, an interior surface, an exterior surface, and a plurality of angularly spaced apart cavities, with each of said cavities defining a longitudinal length and angular width and having an orifice piercing said exterior surface but not piercing said interior surface, with each of said orifices having a longitudinal length less than said longitudinal length of its cavity, and having an angular width less than said angular width of its cavity.
 8. The sleeve of claim 7, wherein at least one from among said plurality of cavities comprises a surface which is a convex floor.
 9. The sleeve of claim 8, further comprising a concave surface radially spaced apart from said convex floor.
 10. The sleeve of claim 7 wherein said plurality of cavities is a first plurality of cavities, and further comprising a second plurality of cavities longitudinally spaced apart from said first plurality of cavities.
 11. The sleeve of claim 10, wherein said second plurality of cavities is radially offset from said first plurality of cavities.
 12. The sleeve of claim 10, further comprising a third plurality of cavities longitudinally spaced apart and radially offset from said second plurality of cavities, such that a first cavity from said first plurality of cavities, a first cavity from said second plurality of cavities, and a first cavity from said third plurality of cavities define a helix along said longitudinal axis. 